The use of a dermal drug delivery composition, such as a topical, transdermal, or transmucosal composition containing a medicament (e.g. a drug), as a means for administering locally or systemically therapeutically effective amounts of the medicament is well known. Exemplary topical compositions include liquids, creams, lotions, salves, pastes, balms, gels and ointments. Exemplary transdermal or transmucosal compositions include flexible-finite systems, such as patches. A typical patch may comprise a transdermal carrier, such as a polymeric pressure-sensitive adhesive or bioadhesive composition, and the medicament. In some cases, the medicament is comprised in the transdermal carrier, such as by the formation of a dispersion, solution or blend of the transdermal carrier formulation and the drug. When the transdermal carrier comprises an adhesive, such as a pressure-sensitive adhesive or bioadhesive, the adhesive functions to adhere the composition directly to the skin or mucosa. Generally, the adhesive adheres effectively to the skin or mucosa and permits migration of the medicament from the carrier to the site of application and/or through the skin or mucosa and into the bloodstream of the patient.
Topical or transdermal (or transmucosal) drug delivery permits controlled release of a drug into a patient without directly invading the patient's body. This mode of administration can conveniently and effectively deliver drug doses in a passive and continuous manner over the course of hours, days, or weeks. Typically, a transdermal drug delivery composition can be placed anywhere on the skin, including sites typically concealed by clothing, and is therefore discreet and cosmetically elegant. Its ease of use also increases patient compliance with drug administration. For example, an individual does not have to adhere to a strict oral regimen, perform routine injections or travel to a clinic for treatment.
Topical and transdermal delivery compositions can be designed to achieve particular blood level profiles of the drug, such as steady-state blood level profiles or increasing blood level profiles, such as may be desired for a particular drug or condition. Moreover, the release rate of the drug can be controlled, for example, by the selection of the polymers used in the carrier composition and other components, such as permeation enhancers, crystallization inhibitors, and other components that are well known in the art.
For these and other reasons, a topically or transdermally formulated drug is often perceived as more desirable than traditional drug delivery systems, such as injections and orally-administered tablets. However, it can be difficult to formulate a drug into a composition that will effectively pass through the outer layers of the skin for therapeutically effective administration. For example, non-polar drugs, insoluble drugs, drugs that crystallize in the presence of typical topical or transdermal compositions, and drugs that react with or degrade in the presence of typical topical or transdermal compositions present particular challenges in the context of topical or transdermal administration.
Ketoprofen is a member of the non-steroidal anti-inflammatory drug (NSAIDs) family. The chemical name is 2-(3-benzoyl-phenyl)-propionic acid and the chemical structure is shown below as Formula I:

Ketoprofen is a carboxylic acid compound that readily crystallizes. The crystallization and acid character of ketoprofen present challenges in the preparation of topical or transdermal compositions comprising ketoprofen.
Previous work by the inventor explored the transdermal delivery rate of non-polar ketoprofen derivatives, and found that methyl, ethyl, and isopropyl esters of ketoprofen achieved lower delivery rates than ketoprofen.